TWI540329B - AC load simulator with adjustable compensation voltage - Google Patents

Description

AC load simulation device with adjustable compensation voltage

The present invention relates to circuit design for electronic loads, and more particularly to an AC load simulation device having an adjustable compensation voltage.

AC load simulation devices are used to simulate various actual loads in AC circuits, including resistive loads such as electric heaters; inductive loads such as motors, compressors, etc.; capacitive loads such as power factor controllers; and power rectifying loads Such as electronic products (including televisions, computers, communications electronics, etc.) to understand and test the operating status of AC power supply units or power components under specific loads.

In general R&D process and testing of AC power supply equipment and power components, it is often impossible to know and test the electrical characteristics, reliability, stability and safety under reactive load or specific load characteristics. Spend a lot of time and manpower and materials to conduct research.

Although a combination of passive components such as inductors and capacitors can be used to simulate negative Load characteristics, or connected to the actual load to test, but this test method is very cumbersome, difficult to combine, difficult to adjust and power capacity expansion is not easy to grasp, can not grasp its temperature characteristics, it is very inconvenient and time-consuming and manpower in use.

In order to solve the problems of the prior art, an AC load simulation device has been developed, which can simulate a resistive load, a constant current load or a constant power load in an AC circuit by setting various parameters of the load, so as to understand and test the communication. Power supply equipment, power components, etc. can work under resistive load or specific load, and can also understand the electrical characteristics, reliability, stability and safety information.

Although an AC load simulation device circuit has been developed to simulate various load characteristics in an AC circuit, the prior art load is a resistive load in which the current waveform must be in phase with the voltage waveform, and cannot be solved when the load is set to a capacitive reactance characteristic. Load or an inductive characteristic load. When the load current leads or falls behind the voltage of the AC power supply, the power component in the load enters the off state due to the load current leading or falling behind the voltage of the AC power supply, causing the load current. As an incomplete waveform, the load cannot simulate the capacitive reactance or inductive load, which makes it impossible to test and verify the reactive load of the AC power supply equipment and power components. It is impossible to understand the electrical characteristics under reactive load conditions. Information on stability and safety.

Accordingly, it is an object of the present invention to provide an AC load simulation device having an adjustable compensation voltage for improving the shortcomings of the AC load simulation device in practical applications.

The technical means for solving the problem of the present invention is to provide a positive half cycle compensation voltage generating circuit and a negative half cycle compensation voltage generating circuit between the AC power source and the load in the AC load simulation device circuit, and the positive half cycle compensation voltage generating circuit is connected to the AC power source. The control unit and the positive half-cycle load, the negative half-cycle compensation voltage generating circuit is connected to the AC power supply, the control unit and the negative half-cycle load.

The user can simulate the capacitive reactance, inductive reactance, impedance and arbitrary current waveform in the AC circuit by setting the power factor set value and the load current set value, wherein the power factor setting range is between -1 and +1. When the user power factor setting value is positive, it means that the load current leads the voltage of the AC power source by a phase angle θ; when the user power factor setting value is negative, it means that the load current is behind the voltage of the AC power source. Angle θ.

The positive half cycle compensation voltage generating circuit generates a positive half cycle compensation voltage after receiving the positive half cycle compensation voltage control signal transmitted by the control unit, and combines with the positive half cycle voltage of the AC power source to output a positive half cycle load voltage to The positive half cycle load is such that the voltage of the AC power supplied to the positive half cycle load continues to be a positive voltage.

Similarly, the negative half cycle compensation voltage generating circuit generates a negative half cycle compensation voltage after receiving the negative half cycle compensation voltage control signal transmitted by the control unit, and combines with the negative half cycle voltage of the AC power source to output a negative half. The weekly load voltage is applied to the negative half cycle load so that the voltage of the AC power source supplied to the negative half cycle load continues to be a negative voltage.

Therefore, the load can be set to a capacitive reactance characteristic load or an inductive characteristic load. When the load current leads or falls behind the voltage phase angle of the AC power source, the power component in the load can still maintain the conduction state to obtain the load current. The complete waveform can effectively understand and test whether AC power supply equipment, power components, etc. can work under reactive load or specific load current waveform, and can understand its electrical characteristics, reliability, stability and safety at the same time. And other information.

Please refer to FIG. 1 , which is a schematic diagram showing the circuit structure of the first embodiment of the AC load simulation device with adjustable compensation voltage according to the present invention. As shown in the figure, the AC load simulation device with adjustable compensation voltage of the present invention comprises an AC power detection circuit 1, a load current setting unit 2, a power factor setting unit 3, a control unit 4, and a positive half. The weekly compensation voltage generating circuit 5 and a negative half cycle compensation voltage generating circuit 6.

The input end of the AC power detecting circuit 1 is connected to an AC power source ACV for detecting the voltage V of the AC power source ACV, the positive half cycle period Tp of the power source, and the negative half cycle period Tn of the power source. And according to the received voltage V of the AC power supply AC, the positive half cycle period Tp and the negative half cycle period Tn, an AC power detection signal S1 is output to the control unit 4.

The AC power detecting circuit 1 further includes an analog-to-digital conversion circuit for converting the AC power ACV into a digital AC power supply to the control unit 4. The AC power supply ACV is connected to a positive half cycle load 7 via a positive half cycle load circuit L(p) and to a negative half cycle load 8 via a negative half cycle load circuit L(n).

The load current setting unit 2 provides the user with the load current required for the test, sets a user load current set value S2, and will use The load current set value S2 is output to the control unit 4.

The power factor setting unit 3 provides a positive or negative value of the power factor required by the user according to the test, sets a user power factor set value S3, and outputs the user power factor set value S3 to the control unit 4. The power factor setting range is between -1 and +1. When the user power factor setting value is positive, it means that the positive half cycle load current I1 and the negative half cycle load current I2 lead the voltage V of the AC power source AC by a phase angle θ; when the user power factor setting value is negative, then It indicates that the positive half cycle load current I1 and the negative half cycle load current I2 are behind the voltage V of the AC power source AC by a phase angle θ.

The control unit 4 is connected to the AC power detecting circuit 1, the load current setting unit 2, and the power factor setting unit 3. The control unit 4 receives the AC power detection signal S1 outputted by the AC power detecting circuit 1 and the user load current setting value S2 output by the load current setting unit 2, and the user power output by the power factor setting unit 3. Factor setting value S3.

The control unit 4 generates a load current control signal S(I) to the positive half cycle load 7 and the negative half cycle load 8 according to the user load current set value S2 set by the user, and according to the user power factor set by the user. The set value S3 is generated to generate a positive half cycle compensation voltage control signal S(p) to the positive half cycle compensation voltage generating circuit 5 and a negative half cycle compensation voltage control signal S(n) to the negative half cycle compensation voltage generating circuit 6, wherein The waveform (including size, timing, and width) of the positive half cycle compensation voltage Vp2 and the negative half cycle compensation voltage Vn2 is determined according to the user power factor setting value.

The positive half cycle compensation voltage generating circuit 5 is connected to the control unit 4 and the positive half cycle load 7 for the positive half cycle voltage Vp1 of the AC power source ACV. A positive half cycle compensation voltage Vp2 is generated according to the positive half cycle compensation voltage control signal S(p), and the generated positive half cycle compensation voltage Vp2 is combined with the positive half cycle voltage Vp1 of the AC power supply ACV to output a positive half cycle load. The voltage Vp3 passes through the positive half cycle load circuit L(p) to the positive half cycle load 7 so that the load voltage supplied to the positive half cycle load 7 continues to be a positive voltage.

The negative half cycle compensation voltage generating circuit 6 is connected to the control unit 4 and the negative half cycle load 8 for generating a negative according to the negative half cycle compensation voltage control signal S(n) when the negative half cycle voltage Vn1 of the AC power source ACV is used. Half-cycle compensation voltage Vn2, and the generated negative half-cycle compensation voltage Vn2 is combined with the negative half-cycle voltage Vn1 of the AC power supply ACV, and then outputs a negative half-cycle load voltage Vn3 via the negative half-cycle load loop L(n) to negative The half cycle load 8 is such that the voltage of the alternating current power supplied to the negative half cycle load 8 continues to be a negative voltage.

Referring to FIG. 2, there is shown a schematic diagram of a first embodiment of an AC load simulation device having an adjustable compensation voltage according to the present invention. As shown, the positive half cycle compensation voltage generating circuit 5 includes a diode D1 and a positive half cycle compensation voltage Vp2. The positive terminal of the diode D1 is connected to the AC power supply ACV, and the negative terminal is connected to the positive half cycle compensation. Voltage Vp2. The positive half cycle voltage Vp1 of the AC power source ACV is combined with the positive half cycle compensation voltage Vp2 through the diode D1 to output a positive half cycle load voltage Vp3 and to the positive half cycle load 7.

The negative half cycle compensation voltage generating circuit 6 includes a diode D2 and a negative half cycle compensation voltage Vn2. The negative terminal of the diode D2 is connected to the AC power source ACV, and the positive terminal is connected to the negative half cycle compensation voltage Vn2. The negative half cycle voltage Vn1 of the AC power source ACV is combined with the negative half cycle compensation voltage Vn2 through the diode D2 to output a negative half cycle load voltage Vn3 to a negative half cycle load 8.

The positive half cycle load 7 includes an N channel power element Q1 and a positive half cycle operational amplifier OP1. The N-channel power component Q1 has a gate terminal Q11, a first terminal Q12, and a second terminal Q13. The first terminal Q12 is connected to the positive half-cycle compensation voltage generating circuit 5, and the second terminal Q13 is connected to the current sensing resistor Rd1. Connected to a common load loop L.

The positive half cycle operational amplifier OP1 has an output terminal 11, a forward input terminal 12 and an inverting input terminal 13, wherein the output terminal 11 is connected to the gate terminal Q11 of the N-channel power device Q1 via a resistor R1, and is input in the forward direction. The terminal 12 receives a load current control signal S(I), and the inverting input terminal 13 is coupled to the second terminal Q13 of the N-channel power device Q1.

The negative half cycle load 8 includes a P channel power element Q2 and a negative half cycle operational amplifier OP2. The P-channel power device Q2 has a gate terminal Q21, a first terminal Q22, and a second terminal Q23. The first terminal Q22 is connected to the negative half-cycle compensation voltage generating circuit 6, and the second terminal Q23 is connected to the current sensing resistor Rd2. Connected to a common load loop L.

The negative half cycle operational amplifier OP2 has an output terminal 21, a forward input terminal 22 and an inverting input terminal 23, wherein the output terminal 21 is connected to the gate terminal Q21 of the P channel power device Q2 via a resistor R2, and the positive input Terminal 22 is a load current control signal S(I) and inverse input 23 is coupled to a second terminal Q23 of P-channel power component Q2.

Referring to Fig. 3, there is shown a waveform diagram of respective related signals in the first embodiment of the present invention. In the present invention, a positive half cycle compensation voltage Vp2 and a negative half cycle compensation voltage Vn2 are applied to the voltage V of the AC power source ACV so that the voltage V of the AC power source ACV supplied to the positive half cycle load 7 continues to be a positive voltage.

Similarly, the negative half cycle period Vn1 of the alternating current power source ACV is combined with a negative half cycle compensation voltage Vn2 so that the voltage V of the alternating current power source ACV supplied to the negative half cycle load 8 continues to be a negative voltage. The complete waveform of the positive half cycle load current I1 and the negative half cycle load current I2 is obtained. The positive half cycle load current I1 and the negative half cycle load current I2 are behind the voltage V of the AC power source AC by a phase angle θ.

Please refer to FIG. 4, which is a schematic diagram showing the circuit structure of the second embodiment of the AC load simulation device with adjustable compensation voltage according to the present invention. As shown in the figure, the compensation voltage generating circuit 9 is connected to the control unit 4 and the AC power source ACV, and generates an AC compensation voltage Vs according to the compensation voltage control signal S of the control unit 4, and the AC compensation voltage Vs includes a positive half cycle compensation voltage Vp2. And a negative half cycle compensation voltage Vn2.

The positive half cycle compensation voltage Vp2 of the AC compensation voltage Vs passes through the positive half cycle load circuit L(p) to the positive half cycle load 7 so that the voltage of the AC power supply supplied to the positive half cycle load 7 continues to be a positive voltage, the AC compensation voltage The negative half cycle compensation voltage Vn2 of Vs is from the negative half cycle load circuit L(n) to the negative half cycle load 8 so that the voltage of the AC power supply supplied to the negative half cycle load 8 continues to be a negative voltage.

The circuit design of the positive half cycle compensation voltage generating circuit 5 and the negative half cycle compensation voltage generating circuit 6 is added in the present invention so that the voltage of the alternating current power supply supplied to the positive half cycle load continues to be a positive voltage, and by the negative half The negative half-cycle compensation voltage generated by the weekly compensation voltage generating circuit is such that the voltage of the AC power supply supplied to the negative half-cycle load continues to be a negative voltage, so that the power components in the load are continuously maintained in an on state to obtain a complete waveform of the load current. Effectively understand and test the electrical characteristics, reliability, and stability of AC power supply equipment and power components Qualitative and safety information.

In addition, the present invention can also understand the capacitive reactance, the inductive reactance, the impedance, and the arbitrary current circuit in the AC circuit by setting the power factor setting value to set the positive half cycle load 7 and the negative half cycle load 8 to understand and test the communication. The operating state of the power supply unit or power component under a specific load.

The above is only intended to be illustrative of the present invention and is not intended to limit the scope of the present invention. Therefore, it should be understood that the scope of the present invention is intended to be included within the scope of the invention. Equivalent modifications or substitutions made without departing from the spirit of the invention are intended to be included within the scope of the appended claims.

1‧‧‧AC power detection circuit

11‧‧‧ Output

12‧‧‧ forward input

13‧‧‧Inverted input

2‧‧‧Load current setting unit

21‧‧‧ Output

22‧‧‧ forward input

23‧‧‧Inverted input

3‧‧‧Power factor setting unit

4‧‧‧Control unit

5‧‧‧ positive half cycle compensation voltage generation circuit

6‧‧‧negative half cycle compensation voltage generation circuit

7‧‧‧ positive half-week load

8‧‧‧negative half-cycle load

9‧‧‧Compensation voltage generation circuit

ACV‧‧‧AC power supply

D1, D2‧‧‧ diode

I1‧‧‧ positive half cycle load current

I2‧‧‧negative half cycle load current

L‧‧‧Common load circuit

L(n)‧‧‧n negative half cycle load circuit

L(p)‧‧‧ positive half cycle load loop

OP1‧‧‧ positive half cycle operational amplifier

OP2‧‧‧negative half-cycle operational amplifier

Q1‧‧‧N channel power components

Q11‧‧‧ gate extreme

Q12‧‧‧ first end

Q13‧‧‧ second end

Q2‧‧‧P channel power components

Q21‧‧‧ gate extreme

Q22‧‧‧ first end

Q23‧‧‧ second end

R1, R2‧‧‧ resistance

Rd1, Rd2‧‧‧ current sense resistor

S‧‧‧Compensation voltage control signal

S(I)‧‧‧ load current control signal

S(n)‧‧‧negative half-cycle compensation voltage control signal

S(p)‧‧‧ positive half cycle compensation voltage control signal

S1‧‧‧AC power detection signal

S2‧‧‧User load current setting

S3‧‧‧User power factor setting

Tp‧‧‧ positive half cycle

Tn‧‧‧negative half-cycle cycle

V‧‧‧ voltage

Vn1‧‧‧ negative half cycle voltage

Vn2‧‧‧negative half cycle compensation voltage

Vn3‧‧‧ negative half cycle load voltage

Vp1‧‧‧ positive half cycle voltage

Vp2‧‧‧ positive half cycle compensation voltage

Vp3‧‧‧ positive half cycle load voltage

Vs‧‧‧ AC compensation voltage

Θ‧‧‧ phase angle

1 is a schematic diagram showing a circuit structure of a first embodiment of an AC load simulation device with an adjustable compensation voltage according to the present invention; and FIG. 2 is a schematic diagram showing a first embodiment of an AC load simulation device with an adjustable compensation voltage according to the present invention; Fig. 3 is a view showing the waveform relationship of respective signals of the first embodiment of the present invention.

4 is a schematic circuit diagram showing a second embodiment of an AC load simulation device with adjustable compensation voltage according to the present invention;

1‧‧‧AC power detection circuit

2‧‧‧Load current setting unit

3‧‧‧Power factor setting unit

4‧‧‧Control unit

5‧‧‧ positive half cycle compensation voltage generation circuit

6‧‧‧negative half cycle compensation voltage generation circuit

7‧‧‧ positive half-week load

8‧‧‧negative half-cycle load

ACV‧‧‧AC power supply

I1‧‧‧ positive half cycle load current

I2‧‧‧negative half cycle load current

L‧‧‧Common load circuit

L(n)‧‧‧n negative half cycle load circuit

L(p)‧‧‧ positive half cycle load loop

S(I)‧‧‧ load current control signal

S(n)‧‧‧negative half-cycle compensation voltage control signal

S(p)‧‧‧ positive half cycle compensation voltage control signal

S1‧‧‧AC power detection signal

S2‧‧‧User load current setting

S3‧‧‧User power factor setting

V‧‧‧ voltage

Vn1‧‧‧ negative half cycle voltage

Vn2‧‧‧negative half cycle compensation voltage

Vn3‧‧‧ negative half cycle load voltage

Vp1‧‧‧ positive half cycle voltage

Vp2‧‧‧ positive half cycle compensation voltage

Vp3‧‧‧ positive half cycle load voltage

Claims (10)

An AC load simulation device with an adjustable compensation voltage, comprising: an AC power detection circuit connected to an AC power source for detecting a voltage of the AC power source, a positive half cycle period of the AC power source, and the AC power source a negative half cycle period, and according to the received voltage of the AC power source, the positive half cycle period and the negative half cycle period, outputting an AC power detection signal, the AC power source is connected through a positive half cycle load circuit a half cycle load and a negative half cycle load connected via a negative half cycle load circuit; a load current setting unit for the user to set a user load current setting value according to the magnitude of the load current required for the test; a setting unit for the user to set a user power factor setting value according to a positive or negative value of a power factor required for testing, and when the user power factor setting value is positive, the load current leads the voltage to a phase angle When the user power factor setting value is negative, the load current lags the voltage by a phase difference angle; a control unit is connected to the AC power source The circuit, the load current setting unit and the power factor setting unit, the control unit receives the AC power detection signal output by the AC power detection circuit and the user load current setting value output by the load current setting unit And the user power factor setting value output by the power factor setting unit, and generating a load current to the positive half cycle load and the negative half cycle load according to the user load current setting value, and according to The user power factor setting value generates a positive half cycle compensation voltage control signal and a negative half cycle compensation voltage control signal; a positive half cycle compensation voltage generating circuit is connected to the control unit and the positive half cycle load for During the positive half cycle of the AC power source, a positive half cycle compensation voltage is generated according to the positive half cycle compensation voltage control signal, and the positive half cycle load is passed to the positive half cycle load to supply to the positive half cycle The voltage of the AC power source of the load continues to be a positive voltage; a negative half cycle compensation voltage generating circuit is connected to the control unit and the negative half cycle load for using the negative half during the negative half cycle of the AC power source The weekly compensation voltage control signal generates a negative half cycle compensation voltage via the negative half cycle load circuit to the negative half cycle load such that the voltage of the AC power source supplied to the negative half cycle load continues to be a negative voltage; The waveform of the half cycle compensation voltage and the negative half cycle compensation voltage is determined according to the user power factor setting value. An AC load simulation device with an adjustable compensation voltage according to the first aspect of the patent application, wherein the AC power detection circuit includes an analog to digital conversion circuit for converting the AC power to a digital AC power supply. To the control unit. For example, the AC load simulation device with adjustable compensation voltage according to Item 1 of the patent application, wherein the user power factor setting value is between -1 and +1. The AC load simulation device with an adjustable compensation voltage according to claim 1 , wherein the positive half-cycle load comprises: an N-channel power component having a gate terminal, a first terminal, and a second terminal. The first end is connected to the positive half cycle compensation voltage generating circuit, and the second end is connected to a common load circuit via a current sensing resistor; a positive half cycle operational amplifier having an output end and a forward input end, An inverting input terminal, wherein the output end is connected to a gate terminal of the N-channel power component via a resistor, and the forward input terminal is connected to the control unit for receiving a load current signal output by the control unit, The inverting input is coupled to the second end of the N-channel power component. An AC load simulation device with an adjustable compensation voltage according to claim 1, wherein the negative half-cycle load comprises: a P-channel power component having a gate terminal, a first terminal, and a second terminal, wherein the One end is connected to the negative half cycle compensation voltage generating circuit, and the second end is connected to the common load circuit via a current sensing resistor; a negative half cycle operational amplifier having an output end, a forward input end, and a reverse An input terminal, wherein the output terminal is connected to a gate terminal of the P channel power component via a resistor, and the forward input terminal is connected to the control unit for receiving a load current signal output by the control unit, the reverse The input is coupled to the second end of the P-channel power component. An AC load simulation device with an adjustable compensation voltage, comprising: an AC power detection circuit connected to an AC power source for detecting a voltage of the AC power source, a positive half cycle period of the AC power source, and the AC power source a negative half cycle period, and outputting an alternating current according to the received voltage of the alternating current power source, the positive half cycle period, and the negative half cycle period The source detection signal, the AC power source is connected to a positive half cycle load via a positive half cycle load circuit, and a negative half cycle load is connected via a negative half cycle load circuit; a load current setting unit is provided for the user to test The magnitude of the load current is set to a user load current setting value; a power factor setting unit is provided for the user to set a user power factor setting value according to the positive or negative value of the power factor required for the test, when the use When the power factor setting value is positive, the load current leads the phase by a phase angle; when the user power factor setting value is negative, the load current lags the voltage by a phase difference angle; a control unit is connected to the alternating current a power detection circuit, the load current setting unit, and the power factor setting unit, the control unit receiving the AC power detection signal output by the AC power detection circuit and the user load output by the load current setting unit a current set value, and the user power factor setting value output by the power factor setting unit, and according to the user load The flow set value generates a load current to the positive half cycle load and the negative half cycle load, and generates a compensation voltage control signal according to the user power factor set value; a compensation voltage generating circuit connected to the control unit and the The AC power source generates an AC compensation voltage according to the compensation voltage control signal of the control unit, and the positive half cycle compensation voltage of the AC compensation voltage passes through the positive half cycle load circuit to the positive half cycle load, so that the supply is positive The voltage of the AC power supply of the half cycle is continuously positive, and the AC compensation One of the voltage negative half cycle compensation voltage is passed through the negative half cycle load circuit to the negative half cycle load such that the voltage of the alternating current power supply supplied to the negative half cycle load continues to be a negative voltage; wherein the positive half cycle compensation voltage and The waveform of the negative half cycle compensation voltage is determined according to the user power factor setting value. An AC load simulation device with an adjustable compensation voltage according to claim 6 wherein the AC power detection circuit includes an analog to digital conversion circuit for converting the AC power to a digital AC power supply. To the control unit. For example, an AC load simulation device with an adjustable compensation voltage according to item 6 of the patent application scope, wherein the user power factor setting value is between -1 and +1. An AC load simulation device with an adjustable compensation voltage according to claim 6 wherein the positive half cycle load comprises: an N-channel power component having a gate terminal, a first terminal, and a second terminal, wherein the One end is connected to the positive half cycle compensation voltage generating circuit, and the second end is connected to a common load circuit via a current sensing resistor; a positive half cycle operational amplifier having an output end, a forward input end, and a reverse An input terminal, wherein the output terminal is connected to a gate terminal of the N-channel power component via a resistor, and the forward input terminal is connected to the control unit for receiving a load current signal output by the control unit, the reverse The input is coupled to the second end of the N-channel power component. An AC load simulation device with an adjustable compensation voltage as claimed in claim 6 wherein the negative half cycle load includes: a P-channel power component having a gate terminal, a first terminal, and a second terminal, wherein the first terminal is coupled to the negative half-cycle compensation voltage generating circuit, and the second terminal is coupled to the common load circuit via a current sensing resistor a negative half-cycle operational amplifier having an output terminal, a forward input terminal, and an inverting input terminal, wherein the output terminal is coupled to a gate terminal of the P-channel power component via a resistor, the forward input terminal Connected to the control unit for receiving a load current signal output by the control unit, the reverse input terminal being coupled to the second end of the P-channel power component.